2(3H)-Benzoxazolone → Tert-butyl [1,1-dimethyl-3-(2-oxobenzooxazol-3-yl)propyl]carbamate

HRID 33373

Reaction equation

HRID 33373 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[NH:3][C:2]1=[O:10].[H-].[Na+].N[CH2:14][CH2:15][C:16]([NH:19][C:20](=[O:26])[O:21][C:22]([CH3:25])([CH3:24])[CH3:23])([CH3:18])[CH3:17].C(=O)([O-])O.[Na+]>CN1C(=O)N(C)CCC1.[I-].C([N+](CCCC)(CCCC)CCCC)CCC.C(OCC)(=O)C>[CH3:18][C:16]([NH:19][C:20](=[O:26])[O:21][C:22]([CH3:25])([CH3:24])[CH3:23])([CH3:17])[CH2:15][CH2:14][N:3]1[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=2[O:1][C:2]1=[O:10]

Participants

8

Reactant 4

HCID 60432(3H)-BenzoxazoloneHCID 24758Sodium hydrideHCID 516892Sodium BicarbonateHCID 45072487tert-butyl N-(4-amino-2-methylbutan-2-yl)carbamate

Product 1

HCID 57435843Tert-butyl [1,1-dimethyl-3-(2-oxobenzooxazol-3-yl)propyl]carbamate

Reagents, catalysts & solvents 3

HCID 67553Tetrabutylammonium IodideCatalystHCID 8857Ethyl AcetateSolventHCID 816462(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl-Solvent

Procedure

4.0 g (29.6 mmol) benzoxazol-2-one are dissolved in 40 mL DMPU and cooled with an ice bath. Under protective gas 897 mg (95%; 35.5 mmol) sodium hydride are added batchwise to this solution. The reaction mixture is heated to ambient temperature and then stirred for another hour. 9.85 g (44.4 mmol) tert-butyl (3-amino-1,1-dimethyl-propyl)-carbamate and 1.97 g (5.3 mmol) tetrabutylammonium iodide are added and the mixture is stirred overnight. The reaction is stopped by the careful addition of sodium hydrogen carbonate solution. Ethyl acetate is added, the aqueous phase is separated off and extracted repeatedly with ethyl acetate. The combined organic phases are washed with sodium chloride solution, dried with sodium sulphate and evaporated down. Purification of the residue by column chromatography (silica gel; petroleum ether/ethyl acetate=7:3) yields the desired product in the form of an oil. Yield 4.1 g (43%); mass spectroscopy: [M+H]+=321.

Workup

  1. temperaturecooled with an ice bath
  2. stirringthe mixture is stirred overnight
  3. customthe aqueous phase is separated off
  4. extractionextracted repeatedly with ethyl acetate
  5. washThe combined organic phases are washed with sodium chloride solution
  6. dry with materialdried with sodium sulphate
  7. customevaporated down
  8. customPurification of the residue by column chromatography (silica gel; petroleum ether/ethyl acetate=7:3)

Sources & evidence

ORD record
ord-ca636d061a034eb9a8bc2731eb253416
Source dataset
uspto-grants-2008_09
Patent number
US07429583B2

Linked notes

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